Science & Environment

'King tides' reign over Bay Area shores

By Daniel M. Jimenez Bay Area News Group

Posted:
12/13/2012 11:49:15 AM PST

Updated:
12/13/2012 05:00:10 PM PST

Click photo to enlarge

Mary Viola and Chris Shafer get close to Thursday's king's tide cresting along the San Francisco Embarcadero at 11 AM, December 13, 2012. The tide measured 7.2 at the Golden Gate and was the highest of the year. (Karl Mondon/Staff)

"'The King Tides.' That's going to be my new band name," Malcolm Smith quipped, before reporting that he hadn't had any reports of serious flooding.

The so-called "king tides" are basically the highest tides of the year, drawn by swings in the gravitational field between the earth and the moon. Winter "king tides" are often accompanied by storms, leading to sharp rises in tides and local flooding, but Thursday's skies were dry across the Bay Area.

Still, the surge provides an important look at the possible effect of changes to the California shoreline and rising ocean levels, according to Sarah Flores, an organizer with the California King Tides Initiative.

"We're looking for the little details about how some changes in water levels can affect everyday life," Flores said, citing reports of a flooded boat launch in Marin and water surging to the tops of piers in Alameda and Berkeley.

With storm surges and flooding caused by Hurricane Sandy still in the minds of many people, the high tides can really focus minds on the possible effects of climate change and erosion, she said.

The tide levels, which peaked around 11 a.m., reached just over 10 feet in Redwood City, a bit above predicted levels, according to the National Weather Service. Off Alameda's shoreline, the high tide came in at 7.9 feet.

By about 6 p.m., the tides are expected to have an equal and opposite effect, hitting deep low tides of as much as -1.8 feet in some areas.

Users on Twitter shared photos of beach areas normally accessible to pedestrians that were under water Thursday morning in San Leandro, Alameda and Sausalito.

Oakland International Airport spokesman Scott Yamasaki said the tides had not had any effect on airport operations. Doug Yagel, a spokesman for San Francisco International Airport, said the same; SFO has protective barriers lining its bayside runways to keep high tides at bay, he said.

The California Highway Patrol did temporarily close a connector ramp about 10:25 a.m. between northbound Highway 101 and northbound Highway 1 in Marin City due to roadway flooding.